I believe that teaching is the best test for knowing if one really understands a concept. Introducing a concept to an unaware audience and answering the questions thrown by them requires thorough understanding of the subject from different angles. Teaching is fun because it is two way learning process where the speaker too learns and appreciates the “non-obviousness” of “obvious” notions while explaining them to the unaware audience.
While preparing material, the speaker goes backward in time and considers several stages of maturity (academic/non-academic), which makes him/her different from the audience. This activity elicits the assumptions and the reasons for those assumptions on which the material is based. In order to have good understanding of a subject, it is extremely important to be aware of such assumptions, which serve as a basis for a theory.
The activity I enjoy most is interaction with the audience. I enjoy knowing point of view of others and resolving queries (if possible).